The conversion of coal to gaseous products of low and higher heating value has been pursued by many technologists over the years. However, coal, because of contaminating metal components, sulfur and nitrogen in the gaseous conversion products, has been regarded by many as a dirty fuel. Removal of sulfur and nitrogen from product gases is costly for which there has yet been no satisfactory economic solution. The conversion of coal has pursued three basic routes involving the production of low BTU heating value gas, medium or high BTU heating value gas; the thermal production of oil from coal which is then treated with hydrogen to remove sulfur from the oil and improve the oil quality; and thirdly, the solvation of coal with the filtering out of ash and pyretic sulfur.
The present invention is concerned with producing a clean gas composition of hydrogen and carbon monoxide from coal which is free of sulfur and nitrogen. A further object of this invention is to produce separate streams of hydrogen and carbon monoxide which can be blended to form any desired ratio thereof for syngas conversion with a Fischer-Tropsch synthesis containing catalysts. Other objects and advantages of the present invention will be more apparent from the following discussion.